This invention relates to curved escalators having a stairway path arcuated in plan and more particularly to segment steps for a curved escalator.
A curved escalator comprises a main frame that defines a stairway path therein along which a plurality of segment steps travel in an endless loop. The stairway path is curved in plan and comprised of upper and lower horizontal landing sections and an intermediate inclined section connecting the upper and the lower horizontal sections. The segment steps circulate along the endless loop in the stairway path. The curved escalator is also provided with a pair of balustrades at both sides of the stairway path. Each of the balustrades has mounted thereon a moving handrail driven around the balustrade in synchronization with the segment steps.
Each of the segment steps is provided with a plurality of horizontal cleats formed on the tread plate and a plurality of vertical cleats formed on the riser. The sets of cleats on one step mesh with another set of cleats on the adjacent connected steps and with comb plates disposed in the upper and the lower landings. While the horizontal cleats on the tread plate have the same center of curvature as the stairway path of the escalator, the vertical cleats formed on the riser are arranged in such a manner that they perpendicularly cross the tread plate. Therefore, even when the radii of curvature of the upper and the lower horizontal sections, the intermediate inclined section, and the upper and the lower transit sections of the curved stairway path are arranged to be different according to the slope or gradient of the sections in order to obtain the smooth movement of the segment steps only the stairway path, the meshing of the cleat sets of the adjacent segment steps is inadequate because of improper configurations of the cleats formed in the segment steps. This causes the disadvantage that the smooth movement of the segment steps along the curved stairway path is impeded.